1. Field of the Invention
The present invention relates generally to the field of molecular biology and medicine. More particularly, it concerns antimicrobial compositions such as, e.g., antimicrobial catheter lock solutions.
2. Description of Related Art
Microbial contamination of medical devices, such as catheters, continues to present a significant clinical problem. Medical devices, such as vascular catheters, have improved the quality of medical care. However, infections resulting from the colonization of organisms embedded in biofilm are the most frequent complication associated with the use of these and other indwelling and/or prosthetic devices. In fact, infections are the most serious complications associated with indwelling central venous catheters (CVCs) (Maki et al., 1998). It is estimated that more than 200,000 catheter-related bloodstream infections (CRBSI) occur annually in the United States alone (Kluger et al., 1999). Staphylococcus epidermidis, Staphylococcus aureus and Candida species are the leading organisms causing CRBSI (Maki et al., 1998; Raad et al., 2002).
While there is a risk of bacterial colonization of a catheter, use of a catheter lock solution can allow continued use of a catheter, and removal of the catheter from a patient is often problematic in many clinical situations. Antimicrobial catheter lock solutions can provide salvage of colonized vascular catheters in the setting of blood stream infections. For many critically ill patients, removal or exchange of a vascular catheter in the setting of blood stream infection is a poor option. There is a risk of vessel irritation or rupture as well as bleeding. The risk of bleeding is particularly significant in patients with underlying coagulopathies such as cancer patients. There is also a risk of cardiac taponade as well as cost associated with radiologic imaging to verify tip position of the replacement catheter. Antimicrobial catheter lock solutions can also serve the valuable function of preventing a catheter from becoming a source of blood stream pathogens in the setting of blood stream infection.
Nonetheless, intralumenal colonization is the major source for the migration of organisms leading to bloodstream infections in long-term silicone catheters (Raad et al., 1993). While progress has been made in reducing bacterial infiltration of medical devices or indwelling medical devices, infections resulting from bacterial colonization of medical devices continues. Clearly, there is a need for new and improved antimicrobial solutions, such as improved antimicrobial catheter lock solutions.